Air conditioning system and controlling method using the same

ABSTRACT

The present invention discloses an air conditioning (AC) system, which comprises an indoor ventilation device, at least one air-supply chain and at least one cascading duct. The indoor ventilation device comprises a main blower. Each of the at least one air-supply chain comprises “n” sub air-supply regions each having at least one air inlet and at least one air outlet. Each of the at least one cascading duct is used to one-by-one cascade each of the “n” sub air-supply regions by sequentially connecting with the at least one air inlet and/or the at least one air outlet of each of the “n” sub air-supply regions, wherein “n” is an integer and “n”&gt;1 and at least one of the at least one cascading duct is a partition wall connecting any two sub air-supply regions.

FIELD OF THE INVENTION

The present invention relates to an air conditioning (AC) system andcontrolling method using the same, and in particular, is related to anAC system applied in a field of AC, for improving the conventional ACsystem.

BACKGROUND OF THE INVENTION

Please refer to FIGS. 1-2. FIG. 1 is a schematic diagram of the pipelineconfiguration of a conventional air conditioning (AC) system 10; FIG. 2is a schematic diagram of the architecture of a conventional airconditioning (AC) system 10. In the conventional air-conditioning system10, an indoor ventilation device 195 is used for air circulation in theindoor space, and the main blower 110 is used to introduce outdoor air190 (generally speaking, the outdoor air 190 is an area where a buildingcommunicates with the outdoors, such as a balcony) and exchange withindoor air to take away harmful substances existing in indoor air, suchas carbon dioxide and formaldehyde. The air is delivered to each subair-supply region 130 through the air inlet 131 through the inlet-airduct 167 in parallel, and then sent back to the indoor ventilationdevice 195 through the air outlet 132 through the outlet-air duct 169.Exhausted air 192 is also discharged as appropriate. Basically, theindoor ventilation device mentioned in the present invention is commonlyknown as a total heat exchanger. Although it has a heat exchangefunction, its main purpose is to maintain indoor air quality and is notsuitable for temperature adjustment. Because the length of the inlet-airduct 167 and the outlet-air duct 169 will affect the air volume(generally, the longer the pipeline, the more serious the loss of theair volume), that the reason why the indoor ventilation device 190 isusually installed in the center of the indoor space (as shown in FIG.1), to avoid the problem of uneven distribution of air volume in eachspace. When design an indoor space, in order to be beautiful, a ceilingis usually used to cover it (the duct, pipeline, the ventilation deviceetc.), which will cause the height of the local or all of the indoorspace to decrease. According to statistics, when the indoor height dropsbelow 2.4 meters, it will cause pressure and discomfort to people.Please refer to FIG. 3, a schematic diagram of the air inlet duct 167and the beam 168. Generally, indoor spaces usually have beams, and theair inlet duct 167 can usually be handled in two ways: 1. Make a hole onthe beam; 2. Form the air inlet duct 167 into a U shape (as shown inFIG. 3); 3. Use a cross-beam flat duct (a flat space is formed under thebeam to allow air to flow). Although the first method is feasible,considering the building regulations and structural safety, thistreatment is usually not recommended; the second and third methods willcause a large amount of air loss, resulting in insufficient ventilationor the need for the rear connection space or retrofit a larger all-heatexchanger.

Furthermore, because under the same air volume, the smaller the pipediameter of the air duct, the greater the air loss. Generally, 6-inch(approximately 15 cm) air ducts are recommended for the indoor space ofhomes. If the second method is adopted, the height of the ceiling needsto be lowered by 20-30 cm from below the beam 168 (it may even benecessary to lower the ceiling).

However, the height of the indoor space is very important for thequality of living. Therefore, if the air duct can be reduced or eveneliminated, there is no need to reduce the height of the ceiling due tothe installation of the air duct. It is important to note that the airducts (inlet-air duct 167 and outlet-air duct 169) of the conventionalair conditioning (AC) air conditioning system 10 usually need to coverthe entire indoor space (as shown in FIG. 1).

Therefore, the conventional technology has below disadvantages: 1. Theuse of a large number of air ducts causes an increase in cost,difficulty in construction, and a decrease in ceiling height in mostindoor spaces; 2. The beam duct will cause the ceiling to decrease(U-shaped duct) or loss of air volume (cross-beam flat duct).

Hence, it is needed to provide an air conditioning (AC) system and thecontrolling method of using the same, for solving the aforementionedtechnical problem.

SUMMARY OF THE INVENTION

In order to solve the aforementioned technical problems of theconventional art, the object of the present invention is to provide anair conditioning (AC) system and the controlling method of the same.First, multiple sub air-supply regions are connected through multiplecascading ducts to supply air sequentially. Compared with theconventional parallel air ducts (the air duct in each sub air-supplyregion needs to be connected to the indoor ventilation device), most ofthe air ducts are reduced. The use of (the length of the duct only needsto be connected to the adjacent sub air-supply region); then further bysetting the cascading ducts in the partition wall between each twoadjacent sub air-supply regions, the need of duct for each two adjacentsub air-supply regions is further greatly eliminated. There is no needto use a large number of air ducts and reduce the height of the ceilingas in the conventional AC system.

In order to achieve the above objective, the present invention providesan AC system, which comprises an indoor ventilation device, at least oneair-supply chain and at least one cascading duct.

The indoor ventilation device comprises a main blower which is used forreceiving an outdoor air. Each of the at least one air-supply chaincomprises “n” sub air-supply regions, each of the sub air-supply regionscomprising at least one air inlet and at least one air outlet. Each ofthe at least one cascading duct is used to one-by-one cascade each ofthe “n” sub air-supply regions by sequentially connecting with the atleast one air inlet and/or the at least one air outlet of the “n” subair-supply regions of each of the at least one air-supply chain. The atleast one air inlet of one of the sub air-supply regions only connectingwith one cascading duct of the at least one cascading duct and the atleast one air outlet of the one of the sub air-supply regions onlyconnecting with another cascading duct of the at least one cascadingduct. Wherein “n” is an integer and “n”>1, air inlet of a first subair-supply region of the “n” sub air-supply regions is connected with anair outlet of the main blower via the at least one cascading duct, anair inlet of a nth sub air-supply region of the “n” sub air-supplyregions is connected with an air outlet of a (n−1)th sub air-supplyregion of the “n” sub air-supply regions, and an air outlet of the nthsub air-supply region of the “n” sub air-supply regions is connectedwith an exhausted air duct and return to the indoor ventilation device.

In one preferred embodiment, at least one of the at least one cascadingduct is a partition wall connecting any two sub air-supply regions.

In one preferred embodiment, when “n” is larger than 2, except for thefirst sub air-supply region and the nth sub air-supply region of the “n”sub air-supply regions, the at least one air inlet of mth sub air-supplyregions of the “n” sub air-supply regions is connected with the at leastone air outlet of (m−1)th sub air-supply regions of the “n” subair-supply regions and the at least one air outlet of the mth subair-supply regions of the “n” sub air-supply regions is connected withthe at least one air inlet of (m+1)th sub air-supply regions of the “n”sub air-supply regions, “m” is an integer and “n” is larger than “m”,“m” is larger than 1.

In one preferred embodiment, the AC system further comprises a sub ACunit disposed inside of the each of the “n” sub air-supply regions.

In one preferred embodiment, the AC system comprises at least one subblower disposed in at least one cascading duct.

In order to achieve the above objective, the present invention furtherprovides a controlling method for an AC system, which comprises: First,an outdoor air is transported through a main blower of an indoorventilation device to at least one air-supply chain; then, at least oneair inlet and/or at least one air outlet of “n” sub air-supply regionsof the at least one air-supply chain are sequentially connected throughat least one cascading duct, each of the “n” sub air-supply regions arecascaded one-by-one, wherein “n” is an integer and “n”>1; then, the airis sequentially transported to each of the “n” sub air-supply regionsthrough the at least one cascading duct; then, air is transported backto the indoor ventilation device by connecting an exhausted duct withair outlet of the nth sub air-supply region. Wherein the at least oneair inlet of one of the sub air-supply regions is only connected withone cascading duct of the at least one cascading duct and the at leastone air outlet of the one of the sub air-supply regions is onlyconnected with another cascading duct of the at least one cascadingduct.

In one preferred embodiment, a sub AC unit is disposed inside each ofthe “n” sub air-supply regions to homogenize the air in the subair-supply region.

In one preferred embodiment, the indoor ventilation device is disposedoutside the at least one air-supply chain.

In one preferred embodiment, at least one of the at least one cascadingduct is a partition wall connecting any two sub air-supply regions.

In one preferred embodiment, the AC system further comprises at leastone sub blower disposed in at least one cascading duct.

Compared with the conventional arts, the present invention merely usesone blower to apply into the method of using at least one cascading ductfor connecting multiple sub air-supply regions. Compared with theconventional parallel air ducts (the air duct in each sub air-supplyregion needs to be connected to the indoor ventilation device), most ofthe air ducts are reduced. The use of (the length of the duct only needsto be connected to the adjacent sub air-supply region); then further bysetting the cascading ducts in the partition wall between each twoadjacent sub air-supply regions, the need of duct for each two adjacentsub air-supply regions is further greatly eliminated. There is no needto use a large number of air ducts and reduce the height of the ceilingas in the conventional AC system.

DESCRIPTION OF THE DIAGRAMS

FIG. 1 is a schematic diagram of the pipeline configuration of theconventional AC system;

FIG. 2 is a schematic diagram of the architecture of the conventional ACsystem of FIG. 1;

FIG. 3 a schematic diagram of the air inlet duct and the beam;

FIG. 4 is a schematic diagram of an AC system according to the presentinvention;

FIG. 5 is an enlarged diagram of portion “A” of FIG. 4;

FIG. 6 is a schematic diagram of the architecture of an AC systemaccording to the present invention; and

FIG. 7 is a flow diagram of a controlling method for an AC systemaccording to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description of the embodiments is given by way ofillustration with reference to the specific embodiments in which theinvention may be practiced. The terms such as “up”, “down”, “front”,“back”, “left”, “right”, “inside”, “outside”, “side”, etc., Thedirection of the diagram. Accordingly, the use of a directional term isused to describe and to understand the present invention and is notintended to limit the invention.

Please refer to FIGS. 4-6. FIG. 4 is a schematic diagram of an AC system100 according to the present invention; FIG. 5 is an enlarged diagram ofportion “A” of FIG. 4; FIG. 6 is a schematic diagram of the architectureof an AC system 100 according to the present invention. The AC system100 comprises an indoor ventilation device 195, at least one air-supplychain 150 and at least one cascading duct 165. There are sub AC units125 in FIG. 4 but no sub AC units 125 in FIG. 6 which is merely forillustration, not limit.

The indoor ventilation device 195 comprises a main blower 110 which isused for receiving an outdoor air 190. Generally, the indoor ventilationdevice 195 comprises basic filter unit (not showed), with the demandchange, the filter unit might be used for eliminating toxic gas such asformaldehyde. Basically, the indoor ventilation device 195 does not havethe function of temperature adjustment. The main function is to providethe indoor space to maintain the concentration of carbon dioxide andother harmful human gases in the indoor space under sort of a closedcondition (doors and windows are closed). In this preferred embodiment,a home space is used for illustration, and only the area in the lowerleft corner (the area where the indoor ventilation device 195 islocated) is a balcony (non-closed space). The air inlet 151 of theair-supply chain region 150 communicates with the main blower 110. Theair-supply chain region 150 includes 6 sub air-supply regions 130 (allin a Para-closed state), and each sub air-supply region 130 includes anair inlet 131 and an air outlet 132 (can be added according to the realsituation).

Each of the at least one cascading duct 165 is used to one-by-onecascade each of the “n” sub air-supply regions 130 for providing air bysequentially connecting with the at least one air inlet 131 and/or theat least one air outlet 132 of the “n” sub air-supply regions 130 ofeach of the at least one air-supply chain 150. The at least onecascading duct 165 sequentially cascades corresponding air outlet 132and air inlet 131 of every two sub air-supply regions 130. FIG. 6 showstwo air-supply chains 150 connected in parallel at the front end(independent air inlet duct 167 can also be used at the front); FIG. 4shows one air-supply chain 150 for Illustrating the present invention.

Preferably, multiple air inlets 131 and/or multiple air outlets 132 canbe provided in each sub air-supply region 130 as appropriate, and it isimportant to note that multiple air inlets 131 and/or multiple airoutlets 132 are connected to the cascading duct 165 in parallel.

It is important to note that each sub air-supply region 130 in thepresent invention is connected to only two cascading ducts 165, and thetwo cascading ducts 165 are respectively connected to multiple airinlets 131 and/or multiple air outlets 132. Therefore, if there are morethan two cascading ducts 165 in one sub air-supply region 130 (that is,more than one cascading duct 165 is used for air-out or air-in), it ispossible to cause the two of the sub air-supply regions 130 which areconnected with the sub air-supply region 130 has insufficient orexcessive air intake (assuming that one cascading duct 165 is used forair-in; two cascading ducts 165 are used for air-out). Therefore,compared with the conventional art, the present invention can maintainthe air exchange rate of each sub air-supply region 130 by restrictingone-in and one-out of each sub-air supply area 130 (one cascading duct165 is used for air-in; one cascading duct 165 is used for air-out).

Preferably, “n” is an integer and “n”>1, air inlet 131 of a first subair-supply region 130 of the “n” sub air-supply regions 130 is connectedwith an air outlet 132 of the main blower 110 via the at least onecascading duct 165, an air inlet 131 of a nth sub air-supply region 130of the “n” sub air-supply regions 130 is connected with an air outlet132 of a (n−1)th sub air-supply region 130 of the “n” sub air-supplyregions 130, and an air outlet 132 of the nth sub air-supply region 130of the “n” sub air-supply regions 130 is connected with an exhausted airduct 170 and return to the indoor ventilation device 195.

When “n” is larger than 2, except for the first sub air-supply region130 and the nth sub air-supply region 130 of the “n” sub air-supplyregions, the at least one air inlet 131 of mth sub air-supply regions130 of the “n” sub air-supply regions 130 is connected with the at leastone air outlet 132 of (m−1)th sub air-supply regions 130 of the “n” subair-supply regions 130 and the at least one air outlet 132 of the mthsub air-supply regions 130 of the “n” sub air-supply regions 130 isconnected with the at least one air inlet 131 of (m+1)th sub air-supplyregions 130 of the “n” sub air-supply regions 130, “m” is an integer and“n” is larger than “m”, “m” is larger than 1.

In FIG. 4, starting from the indoor ventilation device 195, air issequentially delivered to the five sub air-supply regions 130 in acounterclockwise manner. When each sub air-supply region 130 is in aPara-closed state, air can be delivered to each sub air-supply region130 in sequence. In this state, the cascading ducts 165 (air duct) onlyneeds to connect two adjacent sub air-supply regions 130, which canreduce the use of a large number of air ducts compared with theconventional art which using a large number of air inlet ducts and airoutlet ducts. However, despite reducing the use of a large number of airducts, the ceiling height still cannot be increased.

In view of this, a cascading duct 165 can be arranged in the partitionwall 180 of the adjacent sub air-supply regions 130, and there is noneed to use the air duct (series channel 165) connecting the adjacentsub air-supply regions 130. On the premise that the adjacent subair-supply regions can transport air without air ducts, the height ofthe ceiling can be effectively increased.

Finally, referring to FIG. 5 again, a sub blower 120 can be furtherinstalled in the cascading duct 165 to enhance the effect ofventilation. Taking FIG. 6 as an example, a sub blower 120 can beinstalled on some of the partition walls 180 as appropriate. Preferably,the sub blower 120 can be a blower or a fan, because the SERIESair-supply chain (one in and one out) adopted in the present inventionwill not cause uncomfortable noise according to the real implementationof the inventor. And preferably, the blower can be completely installedin the cascading ducts 165 (ie, the partition wall 180), withoutconnecting with ceiling for implementation.

In FIG. 6, the AC system 100 includes two air-supply chains 150. Eachair-supply chain 150 includes five sub air-supply regions 130. (I.e.n=5, m=2-4) Taking the air-supply chain 150 located in the upper half asan example, the “n” sub air-supply regions 130 include a first subair-supply region 130 (the leftmost one) and at least one a second subair-supply area (the rest). The at least one air inlet 131 of the firstsub air-supply region 130 communicates with the air inlet 151 of theair-supply chain 150 (that is, a part of the at least one cascading duct165); then, continue to go through the at least one cascading duct 165.The at least one air outlet 132 of the first sub air-supply region 130is connected to the at least one air inlet 131 of a second subair-supply region 130 (second from the left) adjacent to the first subair-supply region 130; and so on, finally, at the at least one airoutlet 132 of the rightmost sub air-supply region 130 is discharged toan exhausted air duct 170 and sent back to the indoor ventilationdevice. Therefore, each of the at least one cascading duct 165 issequentially connected to the at least one air outlet 132 and/or the atleast one air inlet 131 of each of the “n” sub air-supply regions 130 inthe corresponding air-supply chain 150, and then one by one, each of the“n” sub air-supply regions 130 is connected in SERIES to provide therequired indoor ventilation. In FIG. 6, the exhausted air duct 170 isconnected to the two air supply chains 150 located in the upper andlower halves can be selectively connected or sent back to the indoorventilation device 195 respectively. The following preferred embodimentsalso as in this preferred embodiment, it will not be repeated.

Preferably, a sub AC unit 125 can also be provided in each subair-supply region 130. The sub AC unit 125 here is generally commonair-condition, and mainly provides the function for changing thetemperature. In the preferred embodiment, each sub AC unit 125 isindependent, but it can also be one-to-multiple AC, which is notlimited. Preferably, the sub AC unit 125 does not have a ventilationfunction. Thereby, the indoor ventilation device 195 is responsible forventilation and the sub-air conditioning unit 125 is responsible fortemperature adjustment to maintain the indoor air quality to thegreatest extent. However, in a further step, the indoor ventilationdevice 195 or the sub blower 120 may also have a temperature adjustmentfunction, and it is not limited thereto.

In FIG. 4, it can be seen that when the indoor ventilation device 195 isconnected to the sub air-supply region 130 on the right by the balconyat the lower left corner, the air duct is still used. In actualoperation, since the balcony is generally connected to the toilet orkitchen, Therefore, people are relatively insensitive to the height ofthe ceiling, so in the present invention, the air duct is still used inthis area, because as long as it enters any indoor space (sub air-supplyregion 130), it can be performed by a SERIES air-supply chain toventilating adjacent sub air-supply regions 130.

Comparing FIG. 4 and FIG. 1, it can be clearly understood that theinlet-air duct 167 in FIG. 4 is only a short section, and the length ofthe exhausted air duct 170 (equivalent to the outlet-air duct 169) isalso very long. The short, saved air duct not only reduces materialcosts, but also saves labor and reduces ceiling height because it doesnot require a large number of conventional air duct installations.

In a preferred embodiment, it is assumed that the balcony, the kitchen,and the toilet are respectively from left to right. Generally speaking,the air in the toilet needs to be ventilated independently of otherindoor spaces. Therefore, the partition wall 180 can be used as thecascading duct 165 in the toilet area; that is, the toilet part stilluses the air duct. However, as in the previous paragraph, it shows thatpeople are less sensitive to the ceiling height of the toilet (orkitchen). Even so, the effect of increasing the ceiling height andreducing the installation of air ducts in the ceiling can still beachieved in the remaining main living spaces. In a preferred case, atleast one cascading duct 165 adopts in a partition wall 180 and isprovided with a sub AC unit 125. Because the temperature adjustment isperformed by the sub AC unit 125 after the air enters each subair-supply region 130, energy loss can be reduced (the adjustedtemperature air does not need to be transported over a long distance),so that the temperature of all sub air-supply regions 130 can beconsistent with the set value. At the same time, the sub AC unit 125 cansimultaneously homogenize the air in the sub air-supply region 130 byblowing out the adjusted air. However, in a better case, each subair-supply region 130 of the air-supply chain 150 is in an ideal closedstate (air can only be delivered through the air inlet 131 and the airoutlet 132, and the sub AC unit 125 is also not for ventilation), theair will naturally form a flow direction (the arrow direction in thefig.), because the pressure is closer to the internal ventilation device195 (such as the first sub air-supply region 130 on the right side ofthe balcony).); However, in actual situations, each sub air-supplyregion will not be completely sealed, so arranging the sub blower 120 inthe cascading duct 165 can effectively transport the air from one subair-supply region 130 to another sub air-supply region 130.

Preferably, because there is no need to consider the air volumeattenuation caused by the length of the air duct and the problem ofdifferent air volumes in different sub air-supply regions caused bydifferent lengths of air ducts, the indoor ventilation device 195 can beinstalled outside of the at least one air-supply chain, such as theabove example, can be set in where communicates with the outdoors, suchas balconies, without affecting the ceiling height of the indoor space(sub air-supply region). Taking FIG. 4 as an example, the indoorventilation device 195 can even be installed against the partition wall180 between the balcony (the first left in the lower row) and thekitchen (the second left in the lower row) to save the inlet-air duct167; It is also possible to install the indoor ventilation device 195against the partition wall 180 between the balcony (the first left inthe lower row) and the sub air-supply region above the balcony to savethe outlet-air duct 169. That is, if it is a general industrial orcommercial space (toilet, kitchen, etc., independent exhaust is requiredto avoid affecting the work space), there is no need to use air ducts atall, and the air transmission to the adjacent sub air-supply region 130is completely dependent on the partition wall 180. And because each subair-supply region 130 in the present invention adopts unidirectionalserial connection to connect adjacent sub air-supply regions, to acertain extent, when the air supply volume of the main fan 110 is largeenough, even if the air transmission is only done by the cascading ducts165 in the partition wall 180, air can also be delivered to each subair-supply region 130 in sequence. (As shown in FIG. 4, it will bedelivered to each sub air-supply region 130 in a counterclockwise mannerfrom the balcony in the lower left corner)

FIG. 7 is a flow diagram of a controlling method for an AC systemaccording to the present invention. For the devices mentioned in thiscontrolling method, please refer to FIGS. 3-6, which will not berepeated.

Step S01, an outdoor air 190 is transported through a main blower 110 ofan indoor ventilation device 195 to at least one air-supply chain 150;then, step S02, at least one air inlet 131 and/or at least one airoutlet 132 of “n” sub air-supply regions 130 of the at least oneair-supply chain 150 are sequentially connected through at least onecascading duct 165, each of the “n” sub air-supply regions 130 arecascaded one-by-one, wherein “n” is an integer and “n”>1; then, stepS03, the air 190 is sequentially transported to each of the “n” subair-supply regions 130 through the at least one cascading duct 165;then, step S04, a sub AC unit 125 is disposed inside each of the “n” subair-supply regions 130 to homogenize the air 190 in the sub air-supplyregion 130; then, step S05, the air is transported back to the indoorventilation device 195 by connecting an exhausted duct 170 with airoutlet 132 of the nth sub air-supply region 130.

The at least one air inlet 131 of one of the sub air-supply regions 130is only connected with one cascading duct 165 of the at least onecascading duct 165 and the at least one air outlet 132 of the one of thesub air-supply regions 130 is only connected with another cascading duct165 of the at least one cascading duct 165.

Generally speaking, to evaluate the operation of an air conditioningsystem, all doors are closed as the design standard. For example, inFIG. 4, after all the doors are closed, air can be transmitted to eachspace (sub air-supply region 130) basically in a counterclockwisedirection.

Compared with the conventional art, the present invention only needs tosequentially connect a plurality of sub air-supply regions with aplurality of cascading ducts by a fan to supply air. Compared to theconventional Parallel air ducts (air pipe of each sub air-supply regionneeds to be connected to the indoor ventilation device), the presentinvention reduces the use of most air pipes (the length of the air pipeonly needs to be connected to the adjacent sub air-supply regions); thenfurther by setting the cascading ducts in the partition walls of theadjacent sub air-supply regions, the air ducts needed by the adjacentsub air-supply regions are further removed significantly. There is noneed to use a large number of air ducts and reduce the height of theceiling as in the conventional AC system.

As described above, although the present invention comprises beendescribed with the preferred embodiments thereof, those skilled in theart will appreciate that various modifications, additions, andsubstitutions are possible without departing from the scope and thespirit of the invention. Accordingly, the scope of the present inventionis intended to be defined only by reference to the claims.

What is claimed is:
 1. An air conditioning (AC) system, comprising: anindoor ventilation device, comprising a main blower which is used forreceiving an outdoor air; at least one air-supply chain, each comprising“n” sub air-supply regions, each of the sub air-supply regionscomprising at least one air inlet and at least one air outlet; and atleast one cascading duct, each being used to one-by-one cascade each ofthe “n” sub air-supply regions by sequentially connecting with the atleast one air inlet and/or the at least one air outlet of the “n” subair-supply regions of each of the at least one air-supply chain, the atleast one air inlet of one of the sub air-supply regions only connectingwith one cascading duct of the at least one cascading duct and the atleast one air outlet of the one of the sub air-supply regions onlyconnecting with another cascading duct of the at least one cascadingduct; wherein “n” is an integer and “n”1, air inlet of a first subair-supply region of the “n” sub air-supply regions is connected with anair outlet of the main blower via the at least one cascading duct, anair inlet of a nth sub air-supply region of the “n” sub air-supplyregions is connected with an air outlet of a (n−1)th sub air-supplyregion of the “n” sub air-supply regions, and an air outlet of the nthsub air-supply region of the “n” sub air-supply regions is connectedwith an exhausted air duct and return to the indoor ventilation device.2. The AC system according to claim 1, wherein at least one of the atleast one cascading duct is a partition wall connecting any two subair-supply regions.
 3. The AC system according to claim 1, wherein when“n” is larger than 2, except for the first sub air-supply region and thenth sub air-supply region of the “n” sub air-supply regions, the atleast one air inlet of mth sub air-supply regions of the “n” subair-supply regions is connected with the at least one air outlet of“(m−1)”th sub air-supply regions of the “n” sub air-supply regions andthe at least one air outlet of the mth sub air-supply regions of the “n”sub air-supply regions is connected with the at least one air inlet of(m+1)th sub air-supply regions of the “n” sub air-supply regions, “m” isan integer and “n” is larger than “m”, “m” is larger than
 1. 4. The ACsystem according to claim 1, further comprises a sub AC unit disposedinside of the each of the “n” sub air-supply regions.
 5. The AC systemaccording to claim 1, further comprises at least one sub blower disposedin at least one cascading duct.
 6. A controlling method for an airconditioning (AC) system, comprising: transporting an outdoor airthrough a main blower of an indoor ventilation device to at least oneair-supply chain; connecting sequentially at least one air inlet and/orat least one air outlet of “n” sub air-supply regions of the at leastone air-supply chain through at least one cascading duct, and each ofthe “n” sub air-supply regions are cascaded one-by-one, wherein n is aninteger and “n”>1; transporting the air sequentially to each of the “n”sub air-supply regions through the at least one cascading duct; andtransporting air back to the indoor ventilation device by connecting anexhausted duct with air outlet of the nth sub air-supply region; whereinthe at least one air inlet of one of the sub air-supply regions is onlyconnected with one cascading duct of the at least one cascading duct andthe at least one air outlet of the one of the sub air-supply regions isonly connected with another cascading duct of the at least one cascadingduct.
 7. The controlling method according to claim 6, comprising:disposing a sub AC unit inside each of the “n” sub air-supply regions tohomogenize the air in the sub air-supply region.
 8. The controllingmethod according to claim 6, wherein the indoor ventilation device isdisposed outside the at least one air-supply chain.
 9. The controllingmethod according to claim 6, wherein at least one of the at least onecascading duct is a partition wall connecting any two sub air-supplyregions.
 10. The controlling method according to claim 6, furthercomprises at least one sub blower disposed in at least one cascadingduct.